I. Field of the Invention
The present invention deals of capacitative device for measuring lengths and angles, consisting with a first and second parts arranged in a sliding manner in the direction of displacement and measuring of one part against the other, the first part carrying elongated emitting electrodes, disposed perpendicularly to the said direction, to form a series of at least two receiving electrodes, arranged laterally on each side of this series, the second part being provided with coupling electrodes, facing the emitting and receiving electrodes. An electronic arrangement being implemented in a manner to measure relative displacement of the two parts by means of capacitative coupling through the coupling electrodes between the emitting and receiving electrodes.
II. Description of the Prior Art
Such a device is already known by the German Pat. No. 3340/82, which describes a ruler having two rows of T-shaped coupling electrodes, penetrating each other and completing an efficient coupling, because the coupling surface between the electrodes is large. The coupling electrodes are generally fabricated by means of a laser beam cutting process, for example, which is adequate. The cutting process in this known device is complicated. With this method, it is difficult to obtain a high precision cutout, causing measuring errors. Also, it advantageous to provide for lengthening and shortening of the ruler according to the need of measuring of smaller rulers, by putting them side by side. This juxtaposition method is, however, impossible with the known device.